


Immortal Heart

by SenoraKitty



Series: Like the Tale of a Fish [2]
Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Universe, Alternate Universe - Age of Sail, BAMF John, BAMF Sherlock, Fantasy, John Whump, M/M, Merjohn, Merlock, Mythology - Freeform, Pirate Sherlock, Pirates
Language: English
Status: In-Progress
Published: 2015-05-03
Updated: 2016-01-13
Packaged: 2018-03-28 20:44:46
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 5,013
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3869173
Author URL: https://archiveofourown.org/users/SenoraKitty/pseuds/SenoraKitty
Summary: <blockquote class="userstuff">
              <p>The continuation to "Like the Tale of a Fish." </p><p>Merman John and Pirate Sherlock plan secret rendezvous to learn about each others' mysterious worlds. What they are unaware of are the disasters that their meetings could lead to.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> This sequel has been a long time coming. Since I first worked on "Like the Tale of a Fish" in December I have been wanting to do a follow up story. Finally the first chapter is done.
> 
> I am so excited to post this, I hope you enjoy it. 
> 
> Tags are for the entire story, and additional tags will be added as I go along.

John bobbed in the wake, he could still see the path the pirate's boat cut through the open waters. “Find me again,” the man had said, his rich velvet voice still clear in the merman's ear.

A smirk graced John's lips, and he dove under the waves, following the calm line of water that denoted the pirate's path. He would find the pirate captain, and have him tell John his name.

 

By the time Sherlock arrived at his ship the main deck had been converted into a man made pond; with sails holding in water that had been dredged up, in buckets, from the sea. Sherlock loathed the line-crossing ceremony, but they were ahead of schedule, and the men were looking forward to the celebration. Luckily there was only one pollywog on board during this trip. 

Billy Wiggins, the latest, and youngest addition to Sherlock's crew had in the past been a message carrier for them. The boy grew up along the river side, and made a living gathering information for the captain and his crew when they were out to sea.

Unfortunately the young man had got himself in a spot of trouble with authorities the last time Sherlock's ship had been in port. The captain took pity on the young lad, and offered him quarter. Sherlock easily quelled any objections from the crew with the promise that the boy would earn his keep, or perish doing so.

The lad was only sixteen, but could probably pass for twenty. He had a rough life from the start, and it showed in his thin warn features. Despite reservations from the rest of the crew Billy learned fast, and was able to navigate the many decks, sails, and rigging in no time; becoming a core member of the crew. Even so, he was still a greenhorn at sea, and subject to regular taunting by the elder sailors.

Sherlock would have to keep a keen eye on the proceedings to insure the men did not go too far in their hazing. His presence alone would ward away any ill intent on the boy.

Originally he had objected to the ceremony, feeling the time could have been better spent working. It was Lestrade, the ship's quartermaster, who convinced him to give the men a break. The officer saw it as a reward for such smooth sailing thus far, and hoped the gesture would insure high spirits for the remainder of their journey. Regardless of his own skepticism Sherlock allowed it.

As it turned out Sherlock needn't have feared. Once the preparations had been made the proceedings went off without a hitch. His only condition to the ceremony was that Lestrade be the overseer of the event. It was almost worth it to see Lestrade ridiculously dressed and portraying The King of the Sea, with the ship's carpenter, Mike Stamford, at the God's side playing the role of his fair wife.

Billy had received no worse then some teeth full of tar, and a terrible fright from falling blindfolded from the forecastle into his waiting baptismal on the main deck. The boy arose sputtering and flailing to join his other shellback brethren whom were cheering and splashing about from the sidelines.

While Sherlock was not fond of the tradition, he did not mind the festivities that followed. The crew danced, sang, and drank. Some brought up their instruments from below deck to add a bit of music to the merriment.

With the lanterns lit on deck the party continued well into nightfall.

Sherlock kept his distance from the rowdy crewmen. With his supervision of the ceremony now done he preferred to be left to his own devices. He stuck to the bulwark, nursing a glass of the wine he had retrieved earlier in the day. As he stared at the rich liquid swirling in his cup he thought back on the merman, John, that he had met while recovering said alcohol for the festivities.

Looking out over the dark ink black waters his mind wondered where John was: if the merman was still gliding along under the surface in a world barely touched by man, or if he had kin- a mate and family to return to. There was so much he did not know about the creature, and the regret of not knowing felt like a splinter in his mind.

Distantly Sherlock was aware of a presence at his back, and moving closer into his personal space. Glancing over his shoulder he acknowledged the silver haired man approaching from the gathering of crewmen a few yards away.

Lestrade strolled up smiling hesitantly, a familiar wooden case held carefully in one hand. “The lads were wondering if the captain wouldn't mind gracing us with one of his tunes.”

Sherlock eyed his violin case, his cold gaze sliding up to the sailor's nervous face. Lestrade was the most trustworthy man aboard the ship, but the thought of anyone in his cabin without permission still unsettled the captain's nerves. There were delicate things in his quarters that should not be tampered with.

With a glare he silently conveyed his displeasure at the crewman's actions. The uneasy shifting in the man's body served as both an unspoken apology, and assurance that it would not be happening again.

Taking a long pull from his cup of wine, Sherlock leaned back more comfortably against the ship's railing. “Were they now?” He asked in cold disregard.

Lestrade blew a gusty sigh, he was obviously weary from the day's events. Apparently pretending to be a god could take it out of a man. “Come now, you can't be so rigid all the time. This is a chance to be happy, to enjoy yourself!”

Sherlock arched a single brow at that. “What makes you think I am not enjoying myself?”

“Because of everyone on board you're the only one bone dry from the ankles up.”

It would seem the crew was no longer satisfied with him permitting the festivities, now they wanted him to participate as well. He might as well preform and get it over with.

With a heavy sigh Sherlock took one last sip from his wine. Reluctantly he reached for his violin case in the quartermaster’s grasp. 

Instrument in hand, he strolled over to the other musicians as they were wrapping up one of their shanties. He set his case gently on an upturned bucket, fastidiously ignoring the clamor from the other men. 

Angelo, their cook, called for silence among them. “The captain is going to play us one of his fine melodies on his Stradivari! This is a rare treat for all of us!” The large Italian man gave Sherlock a nod, handing the stage over to the captain.

Cheers and whistles erupted from the crowd before a hushed silence fell. They waited with baited breath for their captain to begin playing. If it was one thing that brought Sherlock and his men together it was their love of the sea, and music. Even while their taste in musical entertainment lay miles apart.

Unlatching the clasps, holding the wooden case shut, he lifted the lid revealing one of his most prized possessions. The polished spruce and maple glinted in the lantern light as he drew the instrument from its velvet lined cradle. Taking up his bow he closed his eyes and began to play. 

It was nothing as fast or spirited as the shanty before, instead he played a more delicate tune. The song he wove was as melodious as the sea itself. He remembers composing the piece when he was younger and lived by the shore. The call of the sea spoke to his heart even then, and he wrote down this song in answer, speaking through music how he longed to be a part of the ocean waves.

As the melody drew to an end Sherlock slowly opened his eyes, casting his gaze back out over the now moonlit waters. A glimpse of movement by the gunwale caught his eye, and he froze. His mind stuttered for a moment thinking he had seen someone on the other side of the bulwark.

Glancing around it seemed none of his men were the wiser. The crew was merrily clapping and chatting drunkenly over the performance, clearly unaware they were all being observed.

Sherlock nodded encouragingly to the other musicians. “Carry on.” 

Trying not to rouse anyone's suspicion Sherlock hurriedly turned to pack his violin in its case. He knew what he had seen, someone was on the outside of the ship. 

There were always enemies on the high seas, and each of his men had their brushes with the law in one port or another. A ship such as his, with her crew more than half drunk, and unaware was a prime target for an attack. Whether it be from other pirates, or naval fleets.

This could have been a scouting party dispatched to gather information on their intended victims. If Sherlock could dispose of them quickly he might be able to spare himself from the rest of his drunken crew getting in the way. The last thing he needed was any one of his men accidentally getting shot, especially himself. Hopefully they would pass off any of his shooting as him simply having one of his strops, they happened often enough.

Once secured, he hauled his instrument over to the space he had occupied before his concert. Covertly peering over the gunwale, he surveyed the waters below attempting to make out the shape of a longboat parallel to the ship. He fingered the polished handle of his flintlock ready to prep the fire-arm the second he spotted a target.

That's when he saw it, a flash of silvery blue off to his right. Farther down the hull of the ship a familiar form was clinging to the wooden planks. Even hidden in the shadows Sherlock could tell who it was.

“What are you doing here?” He hissed down at the creature below.

The shadows shifted and John's golden tanned face emerged from the shrouded darkness. The light of the moon shimmering in the merman's eyes as he peered up to where Sherlock stood.

John instantly recognized the pirate as the one he had stood off against earlier in the day. Triumphantly he began to slither up the side of the ship, his claws effortlessly keeping a grip on the ship's hull as he pulled himself along. Light glinted off the rippling muscles of the merman's back as he hauled himself to the gunwale.

Sherlock once again found himself begrudgingly in awe of the raw power behind the merman's physique. For once his entire body was in full view.

The merman's tail was much longer than Sherlock would have expected. It was nearly twice the length of John's bronzed torso, sleek and shining blue in the moonlight. Much like the rest of merman it was thick and sturdy with sharp looking fins running down its dorsal and tip.

Deftly John propped himself on the chain ledge of the main mast, barely out of reach of the pirate. 

“Your name,” he exclaimed breathlessly. “I came to get your name.”

Sherlock remained awestruck. He did not like feeling of being baffled, but somehow this creature managed to astound him at every turn. 

John mistook the pirate's silence for confusion and began to babble. “I uh- I managed to follow you, that was until the sun went down. I swam for a ways when I spotted your ship, and heard you playing.” His eyes fell keenly on the instrument in Sherlock's hands.

Sherlock blinked at John's omission. The merman had sought his presence from the moment he had directed the creature to come find him. He had not expected such a display of determined curiosity. John had clearly had run ins with humans before so why was he so adamant on seeking Sherlock out?

Squashing the rising tide of questions his mind Sherlock drew himself to his full height, giving off the air of regal authority. 

“Do you have any idea the danger you would be in if one of my men was to spot you?” He inquired dryly.

John finally took notice of the clusters of men near the center of the deck. Licking his lips nervously he turned back to Sherlock. 

His mind began to race down the possible scenarios of what could happen if he was seen. His left shoulder twinged as he remembered the burning steel of a grape shot tearing through his flesh. 

Dread sent a shiver down his spine as he realized he had no idea if this man would shelter him from harm, or let the rowdy crew do what they pleased with him. His fin like ears flattened against his skull in revived panic.

Sherlock could see the creature's anxiety, and while he had no intention of allowing his men to lay a single finger on John, he had to let the merman know exactly the type of position he had put himself in. 

Honestly it was no wonder that the creature had so many wounds marking his body. It was as if he had no sense of self-preservation when it came to humans. A smile tugged at the corner of Sherlock's lips, he could understand the curiosity.

Still the edge of a crowded ship was no place for them to converse, they would need total privacy if they were to quench their shared thirst for knowledge. “Meet me by the rocks, mid-morn tomorrow. There we will talk.” 

With his ultimatum given he turned intending to head back on deck. A sharp tug at his sleeve drew him to a halt.

“Wait!” John hissed, trying to keep his voice low while still conveying a sense of urgency. “Your name, please. It's all I want.”

Sherlock paused to study John; the merman had gone to such lengths to find him after all, and it would be unkind to turn him away with nothing. Gently he withdrew his arm from the merman's loosening grip. 

He answered, his response clipped and precise. “Sherlock Holmes. Captain Sherlock Holmes.”


	2. Chapter 2

**Summary for the Chapter:**

> Sherlock spends time learning about John's people.

**Notes for the Chapter:**

> This has been a long time coming. I am starting to get back into the swing of things, and this fic is at the top of my list. I hope you enjoy!

The plan to elude any questioning of his whereabouts was simple enough. After seeing to it the morning mess crew was well into their duties, Sherlock gave Lestrade the order to hold position while the captain “scouted” the area. His reasoning that their little fore last night might have alerted others in the vicinity to their whereabouts. After all he had thought he saw raiders scouting their ship the night before. He simply declined to tell the quartermaster that the intruder was actually a mythological creature from the deep, and that he was conspiring to meet with the merman within the hour.

Lestrade was well versed in his captain's peculiarities, and while the request to remain stationary while he sussed out potential threats seemed not only risky, but a bit paranoid it was far from the worst of Sherlock's eccentricities. 

The captain sometimes appeared keen on getting himself, and his crew into trouble. However, without fail he was able to get them out of trouble as well. Often times in the most miraculous and unconventional ways. 

For that Lestrade didn't question the captain's leave of absence. Still that did not stop him from advising the captain to take some men with him, to which Sherlock declined stating they would only get in his way. In the end all Lestrade could do was shrug and return to his duties as quartermaster.

Sherlock sat upon the sun beaten rock irritably cursing the whims of sea folk. One such creature in particular was trying his already thin patience.

He had arrived at the rocks not an hour before, and like a fool he had waited, and waited. Only the stray cries of sea birds kept him company as he drug himself from the recesses of his mind palace. He was grateful for only dressing in a thin linen shirt and breeches on his trip out to the rocks because the sun was baking the gritty surface with its sub tropical rays. In the heat of the afternoon even his shirt felt like a sheet of metal plastered to his skin. It was unbearably heavy, and hot on his frame. The only comfort came from the shade of his hat, which he wore low on his brow to keep the sun out of his eyes.

Reaching the end of his patience and on the verge of giving up, he threw one more curse to the sea, and moved to stand. A great splash erupted from the waves behind him.

Sherlock gasped at the shock of coolness on his sun baked skin as water splattered across his thinly clothed back.

A large shadow eclipsed the sun, throwing Sherlock and the rock he knelt upon into shade. Breath caught in the pirate's throat as he glanced up in time to see John, long glistening blue tail and all, leaping over him.

The merman landed with an even louder resounding splash than the one that he had breached out of the water on. His tail hit the crystal waves with a slap that would have been painful to any man, but it did not seem to faze the merman in the slightest. John's deep cobalt tail seemed to slice through the waters like a fine blade, propelling him effortlessly through the depths. It was no wonder that John had managed to catch up to Sherlock and his ship so quickly the day before.

It was evident that John was shamelessly showing off his physical prowess for Sherlock. The creature seemed to feed off Sherlock's appraisal of him. This time being no different than those moments before, when Sherlock found himself in awe of John's feats of strength. Sherlock grudgingly attempted to school his features into a stern moue.

“You know I did say to meet me at mid-morn.” He admonished. “I do have a ship to captain.” It was a weak argument, but one he held onto. His time was precious, and rather than wasting it on the whims of a merman Sherlock would much rather be spending it learning as much as he could from said fish.

John hefted himself onto the rock beside the pirate soaking the surface, and Sherlock's pants with the movement. He found himself apologizing many times before Sherlock seemed to believe his sincerity. 

They settled into a quiet conversation once Sherlock appeared to have forgiven John for being late, and ruining his trousers. They chatted about Sherlock's crew, and the festival John had stumbled upon the night before. He seemed particularly interested in Sherlock's violin playing. To witch Sherlock silently made note to bring his violin with him some time for John to see. Gradually they fell into a companionable silence, both watching the waves roll by.

 

Fiddling with the locket at his breast, a habit the merman seemed to have adapted since Sherlock first gave him the trinket, John slowly worked up the courage to ask the question that had been burning in his mind since he first met the pirate. “You said that there was someone you left behind, is it a mate?” 

Sherlock eyed John as he continued to fidget nervously, knowing exactly where the line of questioning was going. “No, not a lover, just my impertinent brother. If it were up to him I would be back home in England and tied down with a wife and at least two offspring by now.” His lips thinned, his eyes going hard and distant as he thought of his brother. 

As the eldest son it was his brother's duty to insure their family's future. Yet Mycroft saw fit to thrust that responsibility onto Sherlock's shoulders, while he chose to delve into government politics, rather than carrying on the family title. Mycroft was a hypocrite if there ever was one, choosing personal gain while at the same time sneering at Sherlock's ambitions. Jealousy played a large role in his brother's actions; Mycroft loathed the freedom that was bestowed upon Sherlock as the second son. He used his position as the head of family to bully Sherlock into a corner, marry or be disowned.

With a final act of defiance Sherlock took the money from his trust, bought a ship and crew, and set sail with the intention of following his childhood dream of becoming a pirate. If he was to be stripped of his entitlement, and left as a commoner then it was going to be on his terms.

Coming back to the present Sherlock could feel John's eyes on him. He could sense the merman anxiously waiting for him to comment further. No doubt it was the look of annoyance on his features, as he was thinking back on his estranged brother, that was unsettling the creature. 

“You see a man of my profession cannot afford to have friends, much less lovers.” Sherlock hurriedly amended. He watched as John's features softened at the admission, a solemn look replacing the one of alert apprehension.

John absently fingered the locket once more in contemplation. It was apparent that humans and his kind had different views when it came to mating. From what Sherlock had told him males were expected to be present to help rear their young. He had heard of some of his kind following such customs. They would live in family groups much like cetaceans. Even so he had never heard of match making, or forced breeding like Sherlock had described.

“Is that how humans find mates? Their family chooses who they should be with?”

“I take it that is not how your kind-” Sherlock paused looking for the proper term. John had used the word mate so it seemed he was comfortable with the expression. “Find their mates?”

John shook his head before hesitantly adding words to the movement. “No. It's not like that.” He let out a nervous laugh not knowing how to explain the types of relationships his people had. If human courting was strange to him he could only imagine how unorthodox his ways would appear to Sherlock. He was saved the explanation as Sherlock's curt voice cut in. 

“I see, mating must be more natural for you, based on animal instinct.” He made no show to hold back the distaste in his voice. 

“Doesn't matter, It's all plebeian nonsense to me. You see I hold myself to a much higher standard. My brain is the only organ that matters to me, families and mates are much better left to those who have time to squander on fornication. Knowledge is what I crave.”

There was a manic spark in Sherlock's eyes as he carried on, a crazed delight that both unnerved, and excited John. “What kind of knowledge,” he found himself asking aimlessly.

In a flash Sherlock's dagger sharp eyes had John pinned to the spot. “How fast can you swim, how deep, how far can you swim before you need rest or food, what do you eat? I'm assuming it's either fish or some sort of sea plant. Are your people solitary or do you live in pods? Are there others near here? How do you sleep, do you even sleep? How long can you stay out of water? What happens if you exceed this limit?”

John held his breath at the dizzying rush of questions that poured forth seemingly non stop. His heart was pounding at the look in Sherlock's eye it was uneasy feeling as if Sherlock could cut him open and pull out the answers with just a glance. “I don't know...” he breathed feeling as if he were floundering. His heart was thrashing as it would if he were staring down another predictor.

Suddenly the excited look on Sherlock's face fell, replaced by one of outward concern. “What's wrong with you? Why are you doing that?”

“Doing what?” John stammered, confused yet again by the sudden change in Sherlock's demeanor and questioning.

“Your _ears_ are doing that fluttering thing.” Sherlock recalled the movement from when he first set eyes on the merman. It appeared to be a subconscious movement when the merman was confronted by danger. “Do I scare you?”

Indignant at the very idea that Sherlock thought him cowed by his presence John's face grew stoic. His voice settled into a grim tone as he admonished Sherlock of his ridiculous presumption. “I am not afraid, especially not of an unarmed human. I could drag you into the water and kill you in seconds.”

“Great! That answers that question. Drowning your human victims- it would seem that not all the myths are mere frivolity.”

John sputtered at the ecstatic reply. He had expected the pirate to be cowering at his words not elatedly making more assumptions. “Wait a minute- I never said that I've killed a human-” He paused as Sherlock's words settled in, “what myths?”

Disregarding the merman's words Sherlock invaded John's space, the same sharp wild look blazing behind his eyes as he looked at John hopefully. “What do you say, John, are you willing to help me find the answers to my questions? Of course I'll answer what ever nonsensical questions you have about the human race, their rather quite boring, believe me. Not like this.” He eagerly eyed John's tail. “So will you help me?”

“Yes...” John answered slowly not quite sure of what all he was agreeing to. He hated the way he sounded so hesitant, almost as if Sherlock might have been right about him being afraid. If it was one thing John could never be accused of it was being a coward. Even among his fellow people he was considered a risk taker. Often times that labeled him as dangerous, someone who could get others killed if they tried to follow too closely.

John weighed the risks of the pirate's offer. He was much larger and stronger than Sherlock, if the man requested something John was skeptical about the merman simply wouldn't do it. Obviously he meant more to Sherlock alive than he did dead. Committing to a decision he said with much more determination, “I will help.”

“Excellent!” Sherlock leaped from his perch on the rock, and jaunted over to the rowboat which had set idle by the edge of the rocks. 

“Meet me here to morrow at the same time, and don't be late!” He threw over his shoulder as he untied the more line. With jubilant energy he left John by the rocks much the same as he had the day before. However, with a promise to talk again he was sure there would be no unexpected night visits from a curious fish.

 

They met each day around the same time, Sherlock managing to come up with one excuse or another to take the dorey out to the rocks to meet with John. More provisions, scouting, one day the crew didn't even notice he was missing. Lestrade thought he was still in his cabin. It didn't matter though, eventually Lestrade stopped inquiring about his outings. If it weren't for the man's up most loyalty, Sherlock would have feared a mutiny from Lestrade for Sherlock's sudden lack of leadership upon his own vessel.

Together they had managed to answer many of Sherlock's more simple questions. How far could John swim before he needed rest? Sherlock was surprised to hear that John could swim for days before needing rest, and yes he did sleep. Merfolk would find a cove or hidden cave system where they can submerge most of their body in, they would then rest their head in their arms and sleep. Because of this they avoided the deeper reassesses of the ocean, and stuck to shorelines. They could sleep under water, going into a sort of suspended animation near the ocean floor. They would remain vertical while their body slowly shut itself down. It was risky, and taxing on the body to pull itself out of the deathlike sleep. The creature would be ravenous and aggressive due to lack of sustenance. Sometimes attacking and cannibalizing its own kin.

John ate fish as Sherlock had predicted, the amount though was startling. It took a lot of energy to power John's body and in the mornings he would eat a large amount of fish, or krill to keep him going for the rest of the day. That just so happened to be the reasoning behind John's tardiness on their first rendezvous. He had to eat a large amount of fish that morning to make up for his journey to find Sherlock and his ship the night before.

As it turned out merfolk could eat plants, but their bodies were not suited to a vegetarian diet alone. Some consumed plants that would inebriate them much the same way drugs or alcohol would in humans. John admitted this with some disdain, and Sherlock could only deduce that John had dealings with merfolk who partook in dosing themselves with toxic plant life.

Depending on where they were located, and their customs some merfolk did live in family groups. John and his ilk were more solitary, but they did gather during mating seasons, and often visited others they were friendly with. Sherlock learned that there was an actual term for a gathering of merfolk. John had called it a chorus, which in some arbitrary way made sense.

When it came to the question of if there more merfolk near by John was reluctant to answer. The answer was yes, but he made Sherlock swear not to go looking for them. 

With a wave of his had Sherlock dismissed John's insistent demand. “Very well I won't go searching for them. There's no point anyway.” It was true, with John around Sherlock had no need to befriend any other creature. However, that was not going to stop him from sussing out where they lived.

John's answers seemed to pacify Sherlock for some time. The man would only make small inquiries to fill in the blanks in his research. That was until the day Sherlock announced that they'd be doing tests.

**Notes for the Chapter:**

> Comments feed my muse, feel free to leave one!

**Author's Note:**

> Leave a comment and tell me what you think. Grammatical corrections are welcomed.


End file.
